for dreamer and collodi, my first idea would be to take the basic idea of the city, and start to warp it to fit the theme of the masters
dreamer: start to make the ordinary seem fantastic and warped, change the proportions of things like doors, lamps, windows, buildings, they can vary from super basic changes that seem strange to super warped by varying colors and adding outlandish elements like eyes and limbs and stuff sticking out of walls. The idea of the dreamers dreams affecting reality has a lot of potential, as you can have a piece themed to whatever type of dream you want, and vary the intensity.
collodi: a similar idea, start with the basic as a base, but start transforming some buildings and terrain pieces into set pieces like a puppet stage. you could have flat building facades and trees/barrels supported by timber structure on the back, string strung between buildings or wound about lampposts, as well as rolls of it to use as scatter terrain.